In a moment of honesty, he said Tuesday that even he — the Pro Bowl and second-team All-Pro returner who led the league in kick-return average last season — is not assured of a place on the team.

"My spot is not locked up," Smith said.

"That's why I'm going to go out there and give it everything I got, so at the end of the day, if it doesn't work out for me, at least I can say I gave it my all."

At this time last year, it was hard to fathom those words coming from Smith. But the emergence of impressive return candidates coupled with an ultracompetitive situation at running back has left Smith vulnerable.

Kareem Huggins in particular is threatening to shake up the depth chart in the backfield. Once thought to be only a challenger to Smith for the job of No. 3 running back, it's now fair to suggest Huggins could overtake No. 2 Derrick Ward after his impressive camp and preseason opener against the Dolphins on Saturday (eight carries for 55 yards, including a game-high 35-yard run).

If Huggins continues his breakout, it could make Smith unlikely to be used as a running back. That would render him largely just a return man, and the Bucs have other options there, including Huggins, Sammie Stroughter and Micheal Spurlock.

Ward is not out of the woods, either. He is scheduled to earn $3.25 million in base salary this season, and coaches will be watching him closely for the remainder of the preseason.

"You don't want to give anybody any jobs," Morris said. "I think Cadillac has earned the right around here to be the starting running back for a long time with what he's been able to do with his production. But this league has turned into a two-back league, and these guys can really get out there and compete with each other and help each other. (Jobs) always have to be open."

Smith understands that. He has missed time during camp with a strained hamstring that caused him to sit out the preseason opener. This week he returned to practice, fighting through the hamstring discomfort because he knows what's at stake. His absence Saturday came after he spent the final month of 2009 on injured reserve because of his second concussion of the season.

"I'm going to definitely go this week," he said. "I was counting back, and it's been about nine months since I last played in a game. I'm excited, and I'm ready to get back out there and play. I'm tired of sitting out and watching my teammates have fun."

Smith knows Morris is not just giving lip service to him and the others about each one having a chance to become an integral part of the offense behind Williams.

"Everybody in the (unit) has a genuine opportunity to run the ball," Smith said. "We all know that Cadillac is going to be the workhorse of the group, but Cadillac gets tired. … And somebody else is going to have to pick up where Cadillac leaves off at."

There have been years when injuries have forced the Bucs to use their No. 3 running back. Williams' history of severe knee injuries certainly is in the back of the coaches' minds.

"Nobody knew I was going to end up starting in 2007," said fullback Earnest Graham, whose ability to play tailback also factors in the team's roster decisions.

"You have injuries in this game or a number of reasons that can change things. I think everybody is preparing themselves to play because you never know what might bring about a situation where you have to be the guy."

And given that the running backs unit is full of guys who are former long shots — Ward, Huggins, Graham and Smith were either late-round draft picks or undrafted — they know the opposite outcome is possible, too.

"We all know what it feels like," Smith said, "to not know if we're going to have a job the next day."